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Senge MO Hatscher SS Wiehe A Dahms K Kelling A 《Journal of the American Chemical Society》2004,126(42):13634-13635
Vilsmeier formylation is one of the most widely used substitution reactions for the functionalization of porphyrins. However, its utility is limited by the electrophilic/acidic reaction conditions, deactivation of the aromatic system and regiochemical problems, the requirement for metal complexes and necessity for subsequent demetalation under harsh conditions, and low functional group tolerance. To overcome these limitations, the dithianyl group has been utilized as a latent formyl synthon in porphyrin chemistry. 2-Formyl-1,3-dithiane can be used directly in pyrrole condensation reactions to regioselectively yield porphyrins with up to four dithianyl residues. Likewise, 5-dithianyldipyrromethane could be prepared quantitatively as a key building block for various porphyrin condensation reactions yielding the respective free base formylporphyrins after deprotection. Additionally, dithianyllithium can be used as a reagent for the direct aromatic substitution of metallo- and free base porphyrins under nucleophilic conditions. 相似文献
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Stephan T. Hatscher 《Journal of solid state chemistry》2003,172(2):417-423
Single crystals of the title compound were prepared from the elements by a solid state reaction in an iodine atmosphere. Data collection were carried out using a STOE image plate detector at 293 K. The compound crystallizes in the space group P21/n of the monoclinic system isotypically to Tb4[SiS4]3 with four formular units in cells of dimensions: a=986.7(2) pm, b=1099.69(19) pm, c=1646.2(4) pm, β=102.67(3)°. The corresponding residual (all data) for the refined structure is 3.09%.The magnetic behavior of the compound was investigated on powdered samples in a temperature range between 1.7 and 300 K. The deviations from the Curie-behavior could be interpreted by the molecular field approach. 相似文献
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An efficient method for calculating the Lagrange multipliers and the analytical gradients of one state included in a state average MCSCF wave function is presented. It is demonstrated that the state average energy of an ‘equal-weight’ scheme is invariant to rotations within the state average subspace and that the corresponding rotations should be eliminated from the Lagrangian equations. Finally, a diagnostic is presented, which gauges the energy difference between a state defined by a state average calculation and the corresponding fully variational multi-configurational SCF state. 相似文献
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ChemInform Abstract: X-Ray Structural Studies of the Polymorphic Elpasolites K2LiAlF6 and Rb2LiGaF6.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option. 相似文献
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